Functional Characterization Of Abiotic Stress Response Of BpZFP3 In Betula Platyphylla

The zinc-finger protein (ZFP) family is one of the largest family of transcription factors in plants. Based on their structural and functional diversities they have been classified into nine types:C2H2, C8, C6, C3HC4, C2HC, C2HC5, C4, CCCH and C4HC3, respectively. Among them, the C2H2 zinc finger protein is a well-characterized eukaryotic transcription factor that play various roles in many biological processes, including plant growth, development and stress responses. In this study, the expression patterns of 14 BpZFPs in Betula platyphylla and the functional characterization of BpZFP3 were investigated. The main results were as follows:(1) The expression pattern of 14 BpZFPs in root under salt, drought, ABA stresses were investigated by qRT-PCR analysis. The results show that BpZFP3, BpZFP4 and BpZFP12 are strongly induced by high-salt, drought stress.(2) Full-length coding region of BpZFP3 was cloned by PCR, structural analysis indicates that BpZFP3 is C2H2-type zinc finger protein.(3) full-length BpZFP3 CDS lacking a stop codon was cloned into the pGWB5 destination vector using the Gateway TM method and transformed into Arabidopsis genome by the floral dip method, the examination of GFP flurescence signal found that the BpZFP3 is subcellular localized in nucleus.(4) To valid BpZFP3 functions in abiotic stress response, three independent transgenic Arabidopsis lines and wild type plants as control were grown on 1/2 MS agar supplemented with different concentrations of NaCl, Mannitol and ABA. Seedlings from transgenic lines grew better compared to controls,,the germination rate, root length, fresh weight of transgenic lines were significantly higher than those of wild type, and the physiological features including SOD, POD, MDA, Proline content and chlorophyll content of transgenic plants were better compared to controls, suggesting that BpZFP3 functioned during the abiotic treattments.(5) The promoter region with 1822 bp in length of BpZFP3 was cloned, sequence analysis revealed that this region contains a variety of cis-acting elements such as stress responsive, hormone responsive, and light regulation-related motifs etc.The BpZFP3 promoter was fused to the GUS reporter gene to construct plant expression vector and transformed into Arabidopsis thaliana by the instantaneous infection. The staining of transgenic seedings revealed the activity of GUS expression in whole plant.